Graphing Calculator 3D
Visualize

Parameters and Sliders

Create as many variables as you like and use them in graph
equations. When you change the value of a variable either by
typing it down or dragging the slider by mouse, the equations
will be instantly recalculated and its graph redrawn. You can
also assign a range to the variable and then run an animation
that continuously changes the value of one or several variables.

Series and Recursive Functions

You can define functions that have a condition and recursively
call themselves. This powerful feature allows you to define,
compute and plot series and recursive functions easily without
any need to write a script.